Bolt and nut lock



Patented Nov. 4,2

@UNiTED STATES `13.61;"1*ENT oFFicEf".

` WILLIAM R. HEwrrr-or NEwyonx, N; Y. i

BoLr'YANiD! nur Loox Application mea January 1e, 1929. serial No. saznsn My present invention relates to a boltzand nut lock and more particularlyto onejwherein the nut locking meansis' permanently carbe mounted uponand securely held by the bolt. Y n, A'further object of Vmy inventionisto provide a nut'locling means for bolts which will distort the bolty along one axis and thusVv prevent a removal of the nut. f Another object of myinvention is to provide in combination with a bolt having a cylindrical hole in the end thereof, a nut'locking plug' which will completely fill said cylindrical hole and expand the bolt along one axis when rendered operative.'Y i

Agreat many nut locking devices have been devised in the past, butso far as I am aware, the only devices of this character ywhichare in any manner similar 'in construction tomy presentlocking means are those wherein the olt has been provided with an axially extending opening into which either a tapered plug or an over-size, cylindrical plug has been driven. In these cases ythe driving of the vplug into the axialr opening functions to expandf the bolt uniformly into tight engagement with the nut. This expansion does, of

course, tighten the engagement of the nut.

uponV the bolt, but it does not prevent' a removalof the nut even yunder Athese conditions, vas it is then only necessary to apply a greater force to turn the nut olf. As an improvement upon nut locking devices of this character, I

Ypropose to provide a nut locking plugof such acharacter that itwill, in cooperation with VVthe particular shape of opening with which it cooperates, function to distort the bolt alongv one axis and, as a result, render it, and possibly the nut, elliptical so that the two will be `firmly locked against arelative turning move- -ment therebetween.

For a better understanding of myl invention, reference should be had to the accompanying drawing wherein I have shown by va bolt an'd'nut showingthe lockingplugin its normal inoperative position,

. Fig@ is a view'similar to Fig-2 taken along ,a plane at right angles to that of Fig.- 2,V

Fig. 4 isa view similar to `Figzi showing the nut locking plug as driven into its nut locking position, and

Fig. 5` is a. sectional view taken along line V-V of'Fig. 4, lookingv in the direction of arrows, showing `the elliptical configuration of the'bolt when the locking plug is opera tive. 1 1

In the drawing I have designated the bolt by the numeral -10fand a suitable nut therefor by the numeral'11.- -The boltV 10 is vshown as beingprovided with an opening 12 in the end thereof whichextends axially to a depth corresponding to the working, threads of the' bolt ainda suitable plug 13 is also shownas fittedwithin the opening 12.. The axially extendingopening 12 inlthe end of the bolt 10is shown as` cylindrical throughout a portion of its-depth andl tapering'throughout the remaining portion ofits depth. Ihe plug 13 is of such a diameterthat it will fit snugly 'within the cylindrical portion of the opening 12 and be Athussecurely held therein against displacementwhen not. ingoperation'. It will also be noted thattheinnen end of the plug 13 is cut away on oppositevsides to form oppovsitely disposed flat Vsurfaces 14 which, ,in ef- ;fect, render the cross section ofthe innerendl of the plug 13-mor`e or lessell'iptical. A t this f .point -itV shouldbe noted `that fthe portion of the plug13 lying between the flat surfaces 14 ing of the nut uponthe bolt. i In carryingout my invention I propose to `an ellipticallshape and thus prevent a turn-` in the end of the bolt without its becoming loosened and lost, and the tapered portion at the bottom of the hole 11 is so located that itl will expand the bolt at a point adjacent the working threads thereof, this point' being preferably intermediate the top and bottom I surfaces of the nut so that when the plug is driven home it will upset the circularcross section of the tapered portion of the opening 12 and thusexpand the bolt and its threads substantially-elliptically into tight engagement with the nut 11. Y y

From the above it will be seen that when theinner or elliptical end of the plug 13 is driven into the cylindrical, tapered portion 'of the hole 12, the bolt will be extended along one diametrically extending plane and, as a result, contracted along a second Yplane at right angles to the first. This contraction of the bolt along this second plane is, as will be readily understood, provided for by thevcutting away of the plug 13, as previously described, so as to form the inclined surfaces 14.

The particular outstanding features of my invention which I consider of suiiicient importa-nce to Warrant further comment are in the particular design and fit of the plug within the cylindrical portion'of the hole 12 so that the bolt 'and nut locking plug 13 may be assembled and sold as a unit irrespective of thel type of nut which is to be used therewith. A further feature of novelty of my improved lock is also thought to'reside in the particular shape of my improved plugwhich will, as has been stated above, expand the boltJ along one plane andthus renderl it elliptical in crosssection, as, by thus'rend-ering the bolt lock it uponl the bolt 10 by simply driving the plug 13 into the opening 12 flush with the end of the bolt, as illustrated in Fig. 4 of the drawing.

While I have shown the preferred form of my invention as now known to me, it is to be understood that various changes may be made in its construction without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what claim and desire to secure by Letters Patent is` `l. A nut and bolt locking means comprising a threaded bolt provided with a` cylindrical opening having a conical bottom portion formed in the end thereof, a nut for said bolt,

and a plug adaptedto be held by the cylindri cal portion of said opening and driven into the conical portion of the opening to expand said bolt, said plug being cylindrical thro ighout a portion of its length and of a` substantially elliptical cross-section at its inner end whereby when the plug is `driven into the conical portion of said opening the bolt will be expanded along one axis to thereby lock said nut against turning upon said bolt.

' 2. A bolt and nut locking mea-ns comprising a threaded bolt having an opening extending axially into the end thereof, said opening being cylindrical for a` portion ofgits depth and tapering throughout the remaining portion of its depth, and a plug adapted to fit tightly within the cylindrical portion of said opening and be thus held within the end of the bolt with its end projecting outwardly, and means whereby said plug when driven into the tapering portion of said opening will expand the bolt along one axis and cause it to contract on its other axis. Y f VILLIAM R. HEVVITT.

. elliptical in cross section in this manner, a

more secure locking between the nut and boltI will Vbe obtained than would be the case if the bolt were expanded cylindrically in accordance with the disclosures ofthe prior art. y l p The operation of my improved nut locking device is Vcomparatively simple and can be described as follows: It will be assume-d that Lthe bolt has been previously equipped with ner, the bolt will be applied to the particular work intended' and the nut 11 will then be threaded upon the boltjin the ordinary manner. After the nut has been turned up to al Sufficient tightness, the mechanic can then 

